Single handle faucets, commonly referred to as mixer valves, that control both hot and cold water flow have seen vast consumer acceptance. These faucets are commonly constructed such that a handle or knob is movable in two distinct directions to adjust the mix of hot and cold water and to adjust the volume or flow rate.
The two basic types of mixer valves that have seen widest commercial acceptance are plate valves and ball valves. While ball valves offer a reliable compact construction that is durable, plate valves offer a drive mechanism that allows motion to the handle in two desirable directions most universally accepted by consumers. The desirable handle motion allows for an orbiting motion of the handle about a fixed longitudinal axis of the valve body and a rocking, i.e. pivoting, motion about a movable horizontal axis relative to the valve body. The horizontal axis is perpendicular to the longitudinal axis of the valve body and is fixed with respect to the handle such that it moves about the housing as the handle rotates about the fixed longitudinal axis. The one distinguishing characteristic of this type of handle motion is that when the handle is pivoted to an off position, the desired mix ratio of hot and cold water can be remembered by the location of the handle so that when the faucet is turned back on, the same mix of hot and cold water flows through the faucet.
Recently, ball valves have been devised that allow the handle to be operated in the same fashion as the commercially accepted plate type mixer valve. Some of these ball type mixer valves require the introduction of another moving part in the form of a rotatable plate mounted above the ball valve element. Furthermore, these ball valves have been combined with plate devices which can be adjustably positioned about a cover opening through which the handle controls the ball valve to limit the total flow rate. Alternately or in addition, these limiting devices limit the maximum ratio of hot water to cold water and consequentially the maximum temperature of the mixed water at the outlet.
Various disadvantages exist with the above mentioned ball valve construction. In particular, the ball valve element is mounted between elastomeric inlet port seals positioned about the inlet ports of the valve body and a sealing gasket that is mounted under the valve cover or gap. The elastomeric port seals and gasket are all yielding and render a floating characteristic to the ball valve element between the valve body and cap. There is no positive lock or locator mechanism that securely positions the ball valve in place. Because the ball valve can be moved in a translational manner against the elastomeric elements, the operator when operating the handle can also move the handle a small amount in any direction including directions not contemplated in the design of the mixing valve. This unwanted motion renders a undesirable spongy feel to the operation of the faucet and an uncertainty to the operator as to the proper operation of the faucet. Furthermore, the spongy feel of the handle gives the impression that the handle is unstable and not assembled properly.
The top sealing gasket provides three functions. Firstly, it seals against leakage of water about the ball. Secondly, its outer periphery seals against the inner surface of the housing to prevent leakage. Thirdly, the gasket resiliently positions the ball downwardly against the inlet seals. As a consequence, the gasket is an expensive component due to its mass and shape. To obtain a smooth operation, the elastomeric sealing gasket has a thin layer of tetraflouroethylene that contacts the ball valve to reduce wear as compared to direct contact of the elastomeric material with the ball member.
In order to reduce the floating feel, a regulation ring has been incorporated in many ball valve mixing valves. The regulation ring is adjustably screwed onto the valve cap. The regulation ring pushes the sealing gasket downward against the ball valve element which in turn is pressed against the inlet seals. The downward placement of the sealing gasket and ball valve element reduces the undesirable motion but does not eliminate it. Furthermore, the combining of the regulation ring with the known gasket increases the cost and complexity of the mixing valve. The increased pressure exerted in the sealing gasket wears the gasket down. As wear and tear progresses, the regulation ring must be repeatedly adjusted to restore pressure on the gasket to both seal and provide the handle with an operating resistance that maintains it in a stable position against gravitational forces exerted on a faucet handle.
Another ball construction which mimics the desirable handle motion of known plate valves is disclosed in my PCT publication WO 92/22765 published on Dec. 23, 1992 which incorporates a horizontal pin extending through the ball valve to position the ball in the housing. This construction virtually eliminates the floating or spongy feeling during operation of the ball valve faucet.
Cartridges for the valve elements and seals have also been commercially popular. Known cartridges have housed the movable and fixed plate. The cartridge can easily be removed and replaced with another in order to effect an easy repair to the faucet. After the water supply is turned off, the faucet is merely opened and the cartridge is easily replaced. This type of repair can be accomplished without the need to call in skilled labor.
Plate valves have often been incorporated into a cartridge format. However, ball valves have not been amenable to a cartridge construction. Firstly, the floating nature of the traditional ball valve demanded that any cartridge completely surround and capture the ball valve, otherwise the ball valve simply falls out of the bottom of the cartridge. Secondly, the compact nature of the ball valve construction leaves little room for the inclusion of a cartridge. The introduction of traditional cartridges that house and capture the ball into the faucet housing demands that the housing be made taller to incorporate the added height needed for the inclusion of the cartridge.
Furthermore, traditional cartridges inhibit repair to worn elastomeric seals. The cartridge houses both the moving valve element and the fixed valve ports which often include the elastomeric port seals. Most of the wear and resulting leakage in a faucet is the result of the repetitive motion of the moving valve element on the elastomeric port seals. Because the seals are encased in the cartridge, the entire cartridge is replaced including the replacement of many good cartridges components that still have long useful life. The desire to eliminate waste however is offset by the need to simplify the repair operation. Furthermore, many cartridges are permanently assembled and do not permit dismantling.
Even for cartridges that can be dismantled, the advantages of a cartridge is lost if the cartridge was dismantled into all of its component parts. The movable valve element falls out and is often not replaced in its correct orientation. This mis-installation can easily occur for symmetrical plate valves and ball valves which are inherently symmetrical. It takes a knowledgeable and skilled person to avoid mounting certain ball valves in a cartridge in its incorrect orientation.
What is needed is a ball valve cartridge for a mixer valve that houses the upper sealing elements that seal against leakage to the exterior of the housing and seats a ball valve element but allows access to the elastomeric port seals about the inlet ports. What is also needed is a cartridge that seats the movable ball valve element and allows the ball valve to operationally engage a faucet insert that has two valve inlets therethrough that is seated in the faucet body. What is also needed is a ball valve cartridge assembly that can be opened to provide access to the elastomeric seals while retaining the ball valve in a mounted and installed condition with the cartridge.